MXPA06009872A - Process and apparatus for making individually packaged disposable absorbent articles - Google Patents

Abstract

The present invention relates to a process for manufacturing disposable absorbent articles, typically sanitary napkins or pantiliners, which are individually packaged in a bag or pouch. The articles are directly attached to the wrapper material forming the bag or pouch by means of their panty fastening adhesive. The articles are cut from a continuous layered structure, and the cut is made directly through the layer of panty fastening adhesive applied onto the outer surface of the continuous layered structure. The cutting step is carried out with a cutting implement comprising at least one Knife which is internally cooled. The present invention also relates to an apparatus for performing the process.

Description

PROCESS AND APPARATUS TO PRODUCE DISPOSABLE ABSORBENT ITEMS INDIVIDUALLY PACKAGED FIELD OF THE INVENTION The present invention relates to disposable absorbent articles, especially catamenial and panty-protective pads, which are packaged individually before use. Even more especially, this invention relates to a process and apparatus for producing disposable individually packaged absorbent articles.

BACKGROUND OF THE INVENTION Disposable absorbent articles are well known in the prior industry and offer a large number of uses. For example, disposable diapers are intended to absorb and retain urine; the bandages are intended to absorb and retain blood and other body exudates; while the catamenial pads are intended to absorb and retain menstrual fluid. In each case, the disposable absorbent article absorbs and retains liquid, thereby preventing the liquid from soiling, moistening or otherwise contaminating the adjacent area surrounding the liquid discharge point. In general, all disposable absorbent articles have the same basic structure, comprising an absorbent core comprised between a layer of liquid-permeable upper canvas that is in contact with the wearer, which allows the liquid to penetrate its thickness to enter contact with the absorbent core where the liquid is retained, and a lower waterproof element that is in contact with the user's garment. The prior industry teaches numerous variants and additional elements of the basic arrangement of the absorbent core, upper canvas and lower canvas, in which each variant or additional element is directed to improve a specific characteristic of the disposable absorbent article. While there are a large number of variants for the specific structural characteristics of disposable absorbent articles, they are often presented to the user. consumer in the same way. Essentially, the disposable absorbent article, regardless of what specific structural features are used, is packaged in a box or bag from which the consumer removes the item as needed. The problem of protecting the disposable absorbent article once it has been removed from the package in which it is marketed has been treated by the prior industry. The catamenial pads, for example, are usually packaged individually and sold to the consumer in some type of container, usually a bag or a box, containing a convenient number of individually packaged items. For example, in the World Patent Application WO 94/14396, entitled "Fold and Wrap Package for Catamenial Pads Providing Convenient Disposal Means" (Packaging for folding and wrapping catamenial pads that provides convenient means for disposal), an individual package for a catamenial pad that serves to contain it before use and also as a convenient means to dispose of said catamenial pad after it has been used. The individual package comprises a shell configured to have a pocket and a closure flap. The pocket is designed to be able to place inside it a new catamenial pad, generally in a folded configuration, with the flap placed over the mouth of the pocket and attached frangibly to it, for example, with a tongue of adhesive tape for the purpose to close the pocket before use. The container is used by peeling off the flap of the pocket by breaking the frangible unions between the flap and the pocket, removing the new catamenial pad from the pocket and, finally, opening the pocket completely so that the package is a flat wrap. A catamenial pad that has already been used can then be secured to the flat wrap, generally through the adhesive to the undergarment, with the catamenial pad and the wrapper arranged in a waste configuration, generally rolled and folded on themselves, and finally secured in this configuration by fixing the tape tab on another portion of the envelope. U.S. Pat. no. 4,556,146 entitled "Individually Packaged Disposabie Absorbent Article" describes a disposable absorbent article, such as a catamenial pad, associated with a wrap that covers an important surface of the catamenial pad and is adhered thereto so as to can release, usually by means of the adhesive of the catamenial pad that fixes it to the wearer's undergarment. The wrapper is larger than the outer perimeter of the disposable absorbent article so that when the wrapper and the wrap are folded together to form a unit, generally around two fold axes, the respective longitudinal side flaps of the wrapper can be sealed together frangible along common longitudinal edges, thus providing the individual package for the disposable absorbent article. Preferably, the disposable absorbent article is adhered directly to the wrapping, so that it can be released, through the adhesive element that secures it to the undergarment, thereby eliminating the need to provide peel-off paper. Generally, the backing adhesive to the anterior garment, as described in U.S. Pat. no. No. 4,556,146, is provided as a coating of a known pressure sensitive adhesive, in strips or using other suitable patterns such as, for example, a single strip oriented longitudinally and covering substantially the center of the bottom sheet of the catamenial pad. From the point of view of the process, the adhesive coating can, in fact, be applied to the peelable paper and then transferred to the lower canvas of the disposable absorbent article by joining, at the desired position, the removable paper with the lower canvas before forming the individual package, which can be done either in accordance with the world patent WO 94/14396, or in accordance with US Pat. no. 4,556,146, both documents mentioned above. In the latter case, the peelable paper must be permanently adhered to the wrapping material before forming the individual package. Alternatively, the direct application of the adhesive coating on the lower canvas with the desired pattern can be provided, then proceeding to the union of the absorbent article with the wrapping material, which eliminates the need to separately provide the peel-off paper, simplifies the process and saves material. This method is especially suitable for the individually packaged absorbent article according to U.S. Pat. no. 4,556,146. The direct application of adhesive on the lower canvas usually takes place on a continuous weft-like layer structure from which the individual absorbent articles are later formed by cutting them from said structure along the respective desired outer perimeter. The layered structure can already comprise all the elements, namely the layers, which finally form the disposable absorbent article, or some additional elements can be added in a step subsequent to the cutting step. It has been found that in disposable absorbent articles, especially thin ones, such as sanitary napkins and thin pantyhose, the coverage of the undergarment adhesive on the underpants must extend, with reference, pragmatically wings total surface d the lower canvas that is intended to be in contact with the undergarment during use, or at least with portions of the external perimeter of the article, preferably those portions extending along the longitudinal edges of the disposable absorbent article. This represents an advantage in terms of stability during the use of the article, which, in turn, is able to remain in place in the crotch area of the undergarment, where it has been placed by the wearer, and to resist more effectively the efforts and tensions induced by the movement of the user. However, in an individually packaged disposable absorbent article, namely a catamenial pad or a panty protector, the preferred features of the undergarment adhesive covering extend at least partially to the outer perimeter of the absorbent article and the absence of the peelable paper constitute, in combination, two opposing needs, and until now unsightly, from the point of view of the process. On the one hand, in fact, the absence of the peel-off paper necessarily implies the direct layer of adhesive on the bottom canvas. On the other hand, in accordance with the known industry, a patterned adhesive coating, which is accurately recorded with at least part of the outer perimeter of a disposable absorbent article, is not practically feasible, whether the coating is Apply before or after the individual disposable absorbent article has been formed from a continuous weft-like structure by cutting it along the desired external perimeter. The only theoretical alternative is to apply the adhesive coating to the continuous weave structure in such a way that it overlaps the portions of the outer perimeter of the disposable absorbent articles along which the adhesive is to be delivered, and that the subsequent operation Cutting that aims to form and separate the individual items is produced directly through the adhesive layer. As is already known in the industry, this leads to the adhesive sticking to the cutting attachment, with the obvious problems of adhesive buildup on the blade and instability of the process. Surprisingly, it has been discovered that the problem of providing individually packaged disposable absorbent articles in a reliable and simple manner, wherein each article is adhered to the wrapping element so that it can be peeled off without the need to add peelable paper and, moreover, wherein the undergarment adhesive extending along at least part of the outer perimeter of each individual disposable absorbent article can be resolved by combining in a process to provide the disposable absorbent articles without peelable paper and individually packaged , the direct application of the undergarment adhesive to the undergarment layer in a continuous weft-like layer structure, from which the individual disposable absorbent articles and the cutting of the individual disposable absorbent articles of the structure in continuous raster layers at the men Partially through the adhesive layer, at least along the portions of the outer perimeter where the adhesive must be present. The direct cutting through the adhesive layer without the adhesive sticking or accumulating on the cutting attachment is done by applying the cutting technique with a blade that is internally cooled. According to the present invention, there is disclosed a method and apparatus for providing disposable absorbent articles without peelable paper which are individually packaged and having the undergarment adhesive extending along at least part of the respective one. outer perimeter.

BRIEF DESCRIPTION OF THE INVENTION The present invention relates to a process for manufacturing individually packaged disposable absorbent articles; said process comprises the steps of: Providing a continuous weft-like layer structure comprising at least one external structure permeable to liquids, an external structure impermeable to liquids, and an absorbent material placed between the outer structure permeable to liquids and the external structure impervious to liquids, apply a layer of pressure-sensitive adhesive to adhere the garment on at least part of the external structure impervious to liquids, cut individual disposable absorbent articles along a perimeter of the structure in continuous weft layers, wherein the cut is produced at least partially directly through the layer of pressure sensitive adhesive, and wherein the perimeter of each of the individual disposable absorbent articles has substantially longitudinal perimeter segments parallel to a longitudinal axis of absorbent articles discarded Individuals; wherein the cutting step is performed with a cutting implement comprising at least one blade that is internally cooled; adhering, so as to be releasable, each individual disposable absorbent article to its respective wrapping element by means of a layer of pressure-sensitive adhesive; folding the wrapping element around each individual disposable absorbent article; sealing the wrapping element around at least part of the perimeter of each individual disposable absorbent article to form individually packaged disposable absorbent articles. The present invention also relates to an apparatus for performing the above process; said apparatus comprises a cutting implement for cutting individual disposable absorbent articles from a continuous weft-like layer structure; said apparatus comprises at least one blade that is internally cooled.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 shows a continuous weft-like layer structure from which the disposable absorbent articles are formed. Figure 2 shows a disposable absorbent article adhered, releasably, to a wrapping element. Figure 3 shows a disposable absorbent article and a wrapping element partially folded about a first fold axis to form a unit, just before bending them around a second fold axis and sealing them in order to form a disposable packaged absorbent article individually. Figure 4 shows a schematic for illustrating the key components of the process and apparatus of the present invention.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process and to an apparatus for supplying items to b-absorbers of inductive and individually-labeled bursts. As used herein, the term "absorbent article" is related to articles intended to absorb and retain liquids and, in particular, to articles that are placed against or in proximity to the wearer's body to absorb and contain the various liquids excreted from the body, which include, but are not limited to, perspiration, blood, menstrual fluid, urine, vaginal secretions and the like. A "disposable absorbent article" is an absorbent article intended to be disposed of after a single use, ie, it is not intended to be washed or in any other way to be restored or reused. Specifically, the disposable absorbent article is described below in reference to a sanitary napkin or pantyhose. As shown in Figures 2 and 3, the disposable absorbent article 10 referred to in the present invention has a body-facing surface, usually provided with a liquid-permeable outer structure 12, which is often referred to as top canvas; a surface facing the garment, usually provided with an external structure impervious to liquids 14, which preferably is also permeable to gases or water vapor, which is often referred to as a lower canvas; and an absorbent structure 16 (not shown in Figures 2 and 3 for ease of representation, but indicated in the transparency of Figure 1) placed between the body facing surface and the garment facing surface, which It can be called a nucleus to bsorbent. The absorbent article has a longitudinal axis 11 and a transverse axis Il-11 perpendicular to each other, and is delimited by a perimeter 18 having longitudinal perimeter segments 20 corresponding to the perimeter portions 18, which are substantially parallel to the longitudinal axis, and transverse perimeter segments 22 corresponding to the perimeter portions 18, which are substantially parallel to the transverse axis. The absorbent article 10 may also comprise any of the components or features customary in the industry, for example, it may comprise layers and additional elements in addition to those mentioned above. The absorbent article 10, generally a sanitary napkin or panty-towel, is also provided with an adhesive element 24 on the garment-facing surface, usually on the lower canvas 14, which, during use, serves to secure the article absorbent 10 to the undergarment of the wearer thus keeping the article in position against the body of said wearer. The adhesive element 24 is generally a layer of a pressure sensitive adhesive. In the disposable absorbent article 10, the adhesive element 24 is covered with, and adhered to, a wrapping element 28 before use, which forms a pocket or pouch 26 to thereby provide the individually packaged disposable absorbent article 11 mentioned in FIG. the present invention. In order to more fully evaluate the usefulness of the process and the apparatus of the present invention, the following description of a typical disposable absorbent article is provided below.

Upper canvas The upper canvas is moldable, soft to the touch and does not irritate the wearer's skin. Useful upper canvases are well known in the industry and can be made of hydrophobic or hydrophilic fibers which can, for example, be carded, spun by bond, blown by melting or laid in the air. Alternatively, the upper canvas can be a continuous film or sheet of, for example, perforated thermoplastic material. When referring to the upper canvas, they are considered a multiple layer structure or a single layer structure.

Absorbent structure When referring to the absorbent structure, they are considered a multiple layer structure or a single layer structure. Useful absorbent structures are well known in the industry and can be made from a wide variety of materials capable of absorbing and retaining liquids. For example, a wadding of absorbent fibers, a multiplicity of sheets of creped cellulose wadding, or any equivalent material can be used. The known absorbent gelling materials are also, as a rule, included in the absorbent structure. The absorbent capacity of the material used must be sufficient to absorb and retain the expected load of liquid, according to the intended use of the absorbent article, without excessive volume. In a preferred embodiment, the absorbent structure is a thin layered structure comprising two or more fibrous layers and particles of absorbent gelling materials comprised therebetween.

Lower canvas The lower canvas mainly prevents the exudates absorbed and retained in the absorbent structure from wetting the articles that come into contact with the absorbent product, for example, underpants, pants, pajamas and outer clothing. The lower canvas can be made of any flexible material that is impervious to liquids that does not irritate the wearer's skin. Generally, the lower canvas is a sheet of a polyethylene film. Preferably, the lower panel is also permeable to gases or water vapor. When referring to the lower canvas, they are considered a multiple layer structure or a single layer structure.

Adhesive for fastening to underwear The bottom canvas generally forms the garment-oriented surface of the absorbent article, on which the adhesive is placed to attach it to the underwear. The fixing adhesives to the outer clothing may comprise any adhesive or glue used in the industry for these purposes. These adhesives, as a rule, are sensitive to pressure and remain adherent at a temperature well below their application temperature. Suitable adhesives are, for example, Savare LA203 and Savare LA303, manufactured by Savare I.C. from Milan, Italy; Coramelt 867 from Koemmerling in Pirmasens, Germany; Fuller D3964ZP and Fuller H-2238ZP manufactured by H.B. Fuller Co. in Lueneburg, Germany, NS34-2823 manufactured by National Starch and Chemical of Bridgewater, N.J. In accordance with the teachings of this invention and with specific reference to Figures 2 and 3, the disposable absorbent article 10 is individually packaged in a bag or pocket 26 before use. The bag 26 is made of a wrapping element 28, per l or h abitual, a p lastic p picle, which generally wraps completely the disposable absorbent article 10 and which the wearer can open to take the absorbent article and use it. The absorbent article 10 is releasably secured to the wrapping element 28 by means of a fastening adhesive to the undergarment, namely the adhesive element 24, thus providing the advantage of protecting the fastening adhesive to the adhesive. the undergarment until it is used to adhere the absorbent article to said undergarment, without it being necessary to add a peelable paper. In accordance with a preferred embodiment of the present invention, the disposable absorbent article individually packaged 11 is configured in accordance with U.S. Pat. no. 4,556,146, namely, as illustrated in Figures 1 and 2 of said document, wherein no peelable paper is added but the disposable absorbent article 10 is fixed directly to the wrapping element by means of the pressure sensitive adhesive which I attach it to the undergarment. Generally, the individual package can be formed, generally, by folding the wrapping element 28 around the single disposable absorbent article 10 and sealing it around at least part of the perimeter of the disposable absorbent article 10. More preferably, in accordance with preferred embodiment of the present invention disclosed in U.S. Pat. no. 4,566,146, the individual package (bag or pocket 26) of the disposable absorbent article 10 is made by folding the wrapping element 28 and the absorbent article 10 fixed thereto to form a unit, ie, they are folded together, the absorbent article 10 remaining in its location with respect to the wrapping element 28. Preferably, the absorbent article 10 and the wrapping element 28 are folded in the longitudinal direction in thirds about two bending axes 30, 30 'substantially parallel to the transverse axis ll-ll of the absorbent article. 10. The wrapping element 28 covers the lower panel 14 of the absorbent article 10 and, preferably and as a rule, has longitudinal side portions 32 extending beyond the longitudinal perimeter segments 22 of the absorbent article. The respective longitudinal side portions 32 of the wrapping element 28 are frangibly sealed to each other along common longitudinal edges using any of the well-known sealing techniques such as, for example, heat sealing, ultrasonic sealing or shirring, with In order to form the individual container. Figure 3 shows the disposable absorbent article 10 and the wrapping element 28 partially folded around the first fold axis 30 ', just before the last third of the absorbent article 10 and the wrapping element 28 are folded around the second line of folding 30 to form a unit, in the direction indicated by the arrow. Figure 4 schematically illustrates a process and apparatus in accordance with the present invention for producing individually packaged disposable absorbent articles. A continuous weft-like structure 34 is provided from which, according to a preferred embodiment of the present invention, the disposable absorbent articles 10 are obtained by cutting said structure around a predetermined contour to obtain the shape desired, and is transported in the machine direction indicated by an arrow following a marked transport path. The continuous-frame type structure 34 is illustrated in greater detail in Figure 1, which shows the basic components of this structure. The continuous weft-like layer structure 34 generally comprises as individual layers the elements that will eventually form the disposable absorbent article 10, and which are identified in Figure 1 with the same numbers as shown in the absorbent article of Figure 2, and with the same denominations, with the exception that the element identified with the same number corresponds to a single element of the finished disposable absorbent article 10 of Figure 2, and to a generally continuous structure or layer of Figure 1, from which the individual absorbent articles are obtained by a cutting process. This, of course, does not exclude that certain elements, such as, for example, the absorbent core, as illustrated in Figure 1, may alternatively be provided, in accordance with some embodiments, as separate elements already present in the frame-like layer structure. continuous of Figure 1. Specifically, Figure 1 also shows, for clarity, the predetermined contour along which the individual disposable absorbent articles of the continuous weft-like structure are finally cut, which is indicated by a dotted line 40, which at its once corresponds to the desired shape for the individual disposable absorbent articles. This form is an hourglass shape, as illustrated in Figures 1 to 4, but the shapes can be varied, as is known in the industry. The continuous weft-like layer structure 34 of Figure 1 comprises a liquid permeable outer layer 12, intended to form the upper canvas of the finished article; an outer layer impermeable to liquids 14, provided to form the lower canvas of the finished article; and an absorbent structure 16, which is placed between the liquid-permeable outer layer 12 and the liquid-impermeable outer layer 14, and which are provided in the embodiment of Figure 1 as separate elements between the two outer layers. The continuous weft-like layer structure may also comprise additional elements and layers, as well as, alternatively or in combination, a continuous absorbent structure, as is known in the industry. An adhesive application unit 36 applies a layer of pressure-sensitive adhesive 38 in a preferably continuous strip on the liquid-impermeable outer layer 14 of the continuous weft-like structure 34. In general, the application unit of adhesive 30 is a hot melt coating unit, for example, preferably a coating apparatus for bar application of a layer having the desired thickness of the hot melt pressure sensitive adhesive preferred over the liquid impermeable outer layer 14. Alternatively, other known methods for applying the adhesive may be used, for example, methods in which the adhesive does not act on contact, such as hot melt spraying. According to a preferred embodiment of the present invention, the pressure-sensitive adhesive 38 is applied in a continuous strip that is slightly narrower than the continuous-frame type structure 34, as indicated in Figure 1, which it actually represents a portion of the continuous weft-like structure 34 after the application of the pressure-sensitive adhesive 38. The width of the continuous strip of the pressure-sensitive adhesive 38 can be appropriately adapted, such as, for example, in the final individual disposable absorbent article 10 cut from the continuous weft-like layer structure 34, wherein the adhesive covers most of the liquid impervious outer layer 14, ie, the bottom sheet, leaving two areas without adhesive. in both transverse ends of the article; alternatively, an adhesive-free area can be provided at only one of the transverse ends of the article 10, or at different locations along the perimeter 18, as can be easily determined by a person with experience in the industry. An adhesive-free area along the perimeter 18 offers the advantage of a finished absorbent article 10 with a free edge, not adhered to the substrate, i.e., respectively to the wrapping element before use and to the undergarment during use. The user can easily take this free edge in order to separate the article from the respective substrate. The maximum depth of the adhesive-free area or areas 42 can be suitably selected, for example, between 1 mm and 20 mm, preferably between 5 mm and 15 mm, more preferably about 10 mm. The continuous weft-like layer structure 34 having applied the layer of pressure-sensitive adhesive 38 is transported to the cutting unit 44 comprising a cutting implement provided with at least one blade. Generally, as illustrated in Figure 4, the cutting unit 44 comprises a knife roller 46 and a counter roller 48 (anvil roller). The knife roller 46 comprises a series of blades 50, each with a shape that truly corresponds to the perimeter along which the individual disposable absorbent articles of the continuous weft-like structure 34 will be cut, and which will ultimately correspond to the perimeter outer 18 of the disposable absorbent articles 10. The blades 50 are provided for cutting the continuous weft-like structure 34 directly through the layer of pressure-sensitive adhesive 38. In order to prevent the build-up of adhesive and the latter stick to the cutting attachment, the blade is internally cooled to a temperature that is generally lower than the dew point in the working conditions. This cooling causes the formation of water condensation on the surface of the blade of the blade, which prevents the adhesive from sticking to the blade. Generally, in the embodiment illustrated in Figure 4, the entire blade roller 46 is internally cooled to the desired temperature. The cutting material 52, 52 'which is obtained from the cutting step is then removed for disposal after cutting. Generally, as shown in Figure 4, the two continuous trim strips 52 are separated from the cutting unit 44 and discarded using the known means. The separate elements of the cutting material 52 ', created in the cutting step in the preferred embodiment illustrated in FIGS. 1 and 4, where the items to b-absorbers of individual labels 10 that are created from the structure In continuous weft-like layers 34 are adjacent to each other at two points corresponding to the wider transverse sections in order to save material, they are preferably collected inside counter-roller 48 by, for example, a vacuum system, which does not it is shown in the figures, and they are discarded using the known means. Different means for removing and disposing of the cutting material can also be provided, as can be easily determined by the experienced person, for example, when the individual disposable absorbent articles 10 are cut from the continuous weft structure 34 with a different arrangement. For example, if individual disposable absorbent articles are not cut from the continuous weft-like layer structure 34 adjacent to each other, they are, instead, with a small gap between each subsequent pair of articles, the amount of material The cutout will increase slightly, but it will consist of an element that will have the shape of a continuous stair that can be completely and easily removed from the cutting unit 44 for proper disposal, without the need for a separate device, for example, a vacuum system, for collecting the separate elements of the cutting material 52 ', as shown in Figure 4. After the cutting step, the continuous layer of the pressure-sensitive adhesive 38 provides the adhesive elements 24 on the layer of the bottom sheet 14 of the individual disposable absorbent articles 10 cut from the continuous weft-like structure 34. The adhesive element 24 it extends along substantially the entire length of the longitudinal perimeter segments 20, as shown in Figures 1 and 4. The counter-roller 48 is also provided with a separate system, generally a vacuum system, in order to maintain , after the cutting step, the newly formed individual disposable absorbent articles 10 on the outer surface of the counter roller 48 until they are transferred to the web of the wrapping material 54 and adhere to it, so that they can be released, through of the respective adhesive elements 24 in a coupling unit 56 comprising a pressure roller or squeeze roller 58 which presses the individual disposable absorbent articles 10 onto the wrapping material 54. The squeezing roller 58 may have passages, as shown in FIG. shown in Figure 4, or be cylindrical with a smooth external surface, preferably flexible and elastic. As is known in the industry, the speed of the wrapping material web 54, recorded with the spherical velocity d of the shock roller 58, can be selected appropriately and is, generally, higher than the peripheral speed. of the counter-roller 48, so that the subsequent individual disposable absorbent articles 10 engage with the desired spacing (passage) on the web of the wrapping material 54. The band of wrapping material 54 having adhered the individual disposable absorbent articles 10 then proceeds towards the folding / cutting / sealing units, which are not shown in Figure 4, where individually disposable absorbent articles are formed. This can be done in accordance with known techniques, as can be easily determined by a person with experience in the industry. For example, in a preferred embodiment of the present invention, the web of wrapping material 54 having adhered individual disposable absorbent articles 10 can continue to a folding unit where the web 54 and the articles 10 having adhered are continuously folded in thirds, to form a unit, around two bending axes practically parallel to the direction of travel of the band 54, corresponding to the axes 30 and 30 'illustrated in Figure 2 with reference to a single article 10 adhered in such a way that it can be released to its respective wrapping element 28. Disposable absorbent articles individually packaged are then provided by cutting and sealing the band 54 folded into three parts comprising the individual articles 10 along lines spaced perpendicular to the direction of displacement, which in turn correspond to the longitudinal edges superimposed and sealed between each other of each shell element 28, as shown for example in Figure 3, in a partially folded configuration. Incidentally, the steps can also be performed in the reverse order, that is, first cut each wrapping element 28 that has its respective individual disposable article 10 attached to it, then fold it and seal it to form the bag or pocket 26. In accordance with a Preferred embodiment of the present invention, the counter-roller 48 of the cutting unit 44 can be cooled to avoid the possibility of the adhesive also accumulating on said counter-roller. The cooling of the blade, as a rule, of the entire blade roller 46 and the counter roller 48, can be performed using the known means, for example, through the circulation of a known cooling fluid, such as a solution of water with glycol. Generally, and preferably, the entire blade roller 46 and, optionally, all the counter roller 48 are cooled uniformly, although it is also possible that only selected portions of the rolls are cooled, for example, the roller blades of blades 46 or the areas corresponding to the individual disposable absorbent articles of the counter-roller 48. The actual temperatures at which the blade roller 46 and, optionally, the counter roller 48 must be cooled will depend on the environmental conditions in which the cutting step. Normally, the ambient temperature is between 20 ° C and 30 ° C, preferably at about 25 ° C. The relative humidity is at least 40%, preferably between 40% and 60%, more preferably between 45% and 55%, most preferably about 50%. Under the preferred conditions of such a typical process, the temperature of the knife roller 46 is preferably maintained between 0 ° C and 6 ° C, more preferably between 2 ° C and 4 ° C, most preferably, at about 3 ° C. When, preferably, the counter-roller 48 is also cooled, its temperature is maintained between 5 ° C and 20 ° C, preferably between 7 ° C and 15 ° C, more preferably, at about 10 ° C. It is especially preferred, in order to avoid or limit the formation of condensation of water in the counter-roller areas 48 which are brought into contact with the individual disposable absorbent articles 10 during their transport to the coupling unit 56, that the temperature of the counter-roller , also preferably cooled as described above, is maintained below the temperature of the knife roller 46 ,. with a difference (? T) between 2 ° C and 20 ° C, preferably between 5 ° C and 10 ° C.

In a particularly preferred embodiment of the present invention, under normal ambient conditions of 24 ° C and with a relative humidity of 50%, the temperature of the blade roller 46 is about 3 ° C, and the temperature of the counter-roller 48 is about 10 ° C, with a difference? T of about 7 ° C. According to another preferred embodiment of the present invention, the areas 60 of the blade roller 46 comprised within the perimeters defined by each blade 50 can be removed with respect to the outer surface of the blade roller 46, in order to avoid accidental contact of the roller with the adhesive 38 in said areas 60 and to further reduce the risk of jams occurring in the apparatus, particularly at the high speed normally used in this type of process. The depth of these removed areas is preferably constant and can be adapted appropriately according to the thickness of the individual disposable absorbent articles formed 10, as can easily be determined by an experienced person. The method and apparatus of the present invention have heretofore been described in the arrangement in which the individual disposable absorbent articles are cut from the continuous weft-like layer structure 34 oriented in the transverse direction (CD), ie with the respective longitudinal axes perpendicular to the direction of displacement of the frame structure. Alternatively, the individual disposable absorbent articles can also be cut from the continuous weft-like layer structure with an orientation oriented in the machine direction (MD), and an experienced person will easily notice the respective changes and adjustments necessary for the process and the apparatus. . The adhesive layer applied in a preferably continuous strip can have any preferred width or pattern, with a constant or variable basis weight. Preferably, the application is made in a continuous strip having a constant width and a constant basis weight, as illustrated in the attached figures. The preferred application method is a hot melt coating that is applied with a bar, also known as a groove coating. The adhesive layer can preferably be applied with a basis weight of 10 g / m2 to 40 g / m2, more preferably, of 15 g / m2 to 30 g / m2, even more preferably 20 g / m2 to 25 g / m2 . While particular embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the industry that various changes and modifications can be made without departing from the spirit and scope of the invention.

It has been intended, therefore, to cover in the appended claims all changes and modifications that are within the scope of the invention.

Claims (13)

1. A process for producing individually packaged disposable absorbent articles; The process comprises the steps of: • Providing a continuous weft-like layer structure comprising at least one external fluid-impermeable structure, an external liquid-impermeable structure, and an absorbent material placed between the structure external liquid-permeable and liquid-impervious external structure, • apply a layer of pressure-sensitive adhesive to adhere the garment on at least part of the outer structure impervious to liquids, cut individual disposable absorbent articles from the structure in continuous raster layers along a perimeter; the cut is produced at least partly directly through the layer of pressure-sensitive adhesive; the perimeter of each of the individual disposable absorbent articles has longitudinal perimeter segments substantially parallel to a longitudinal axis of the individual disposable absorbent articles; characterized in that the cutting step is carried out with a cutting implement comprising at least one blade that is internally cooled; adhering each of the individual disposable absorbent articles so that they can be released to a respective wrapping element by means of the layer of pressure-sensitive adhesive; folding the wrapping element around each of the individual disposable absorbent articles; sealing the wrapping element around at least part of the perimeter of each of the individual disposable absorbent articles in order to form disposable absorbent articles individually packaged. A process according to claim 1, further characterized in that the wrapping element has longitudinal side portions extending outwardly from the longitudinal perimeter segments of the individual disposable absorbent article. 3. A process according to claim 2, further characterized in that each of the individual disposable absorbent articles and the respective wrapping elements are folded to form a unit around at least two bending axes practically perpendicular to the longitudinal axis of the pieces. individual disposable absorbent articles, and the longitudinal side portions are frangibly sealed together to form individually packaged disposable absorbent articles. 4. A process according to any of the preceding claims, further characterized in that the wrapping elements are provided from a continuous band of wrapping material. 5. A process according to any of the preceding claims, further characterized in that the layer of pressure-sensitive adhesive is applied as a continuous strip. 6. A process according to any of the preceding claims, further characterized in that the layer of pressure-sensitive adhesive is applied with a basis weight of 10 g / m2 to 40 g / m2, preferably 15 g / m2 to 30 g / m2, more preferably from 20 g / m2 to 25 g / m

2. 7. A process according to any of the preceding claims, further characterized in that the cutting implement is comprised in a cutting unit comprising a knife roller and a counter-roller; the blade roller is internally cooled and comprises at least one blade. 8. A process according to any of the preceding claims, further characterized in that at least one blade is cooled to a temperature between 0 ° C and 6 ° C, preferably between 2 ° C and 4 ° C, with the highest preference at approximately 3 ° C. 9. A process according to claim 7, further characterized in that the counter roller is internally cooled. 10. A process according to claim 9, further characterized in that the counter-roller is cooled to a temperature of between 5 ° C and 20 ° C, preferably between 7 ° C and 15 ° C, more preferably of about 10 ° C. 11. A process according to claim 9 or 10, further characterized in that the temperature of the counter-roller is lower than the temperature of at least one blade, with a difference? T between 2 ° C and 20 ° C, preferably between 5 ° C and 10 ° C. 12. A process according to any of claims 7 to 11, further characterized in that the area of the blade roller, comprised within the perimeter defined by at least one blade, is withdrawn with respect to the outer surface of the blade roller. 1

3. An apparatus for producing disposable individually packaged absorbent articles in accordance with the process of any of the preceding claims; the apparatus comprises at least: A continuous frame-type layered structure supply unit; • an adhesive application unit; a wrapping material supply unit; a cutting unit comprising a knife roller and a counter roller; a coupling unit for adhering, so as to be releasable, individual disposable absorbent articles to the wrapping material; a folding / cutting / sealing unit for forming the disposable absorbent article individually packaged; characterized in that the blade roller comprises at least one blade that is internally cooled.